Method of forming lugs of a crop conditioner roll

ABSTRACT

A method for forming lugs of crop conditioner rolls includes cutting lugs from a piece of cylindrical tube stock having a thickness equal to a desired thickness of the lug and having an inside radius approximately equal to that of a conditioner roll core to which the lug is to be affixed.

FIELD OF THE INVENTION

The present invention relates to crop conditioners, and more particularly relates to a method of forming lugs of such crop conditioner rolls.

BACKGROUND OF THE INVENTION

Mower-conditioners are usually equipped with a pair of counter-rotating conditioner rolls, which cooperate with each other to condition crop fed between them. One of the conditioner rolls is fixed while the other has opposite ends respectively rotatably carried in a pair of support arms mounted for pivoting about a fixed axis so as to move toward and away from the fixed conditioner roll in response to the thickness of the crop mat passing between the rolls. Movement of the moveable roll is resiliently restrained by a biasing assembly acting on the support arms. To effectively condition the crop, it is known to provide the surfaces of the conditioner rolls with various lug configurations, with straight, chevron and spiral patterns being most common. Heretofore, it has been the practice to apply formed lugs to a generally circular piece of tubing, with the lugs being cut and formed to achieve the desired radius. This method of forming lugs has proved to be very difficult, especially with lugs that are relatively long and not straight, i.e., not parallel to the axis of the tubing.

The problem to be solved is how to economically achieve the fabrication of accurately dimensioned lugs of various configurations that will fit on a generally cylindrical piece of tubing.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an improved method of making crop conditioner roll lugs.

A broad object of the invention is to provide a method of making lugs that are dimensioned accurately so as to fit closely to the exterior of a cylindrical tube forming the core of a conditioner roll.

A further object is to provide a method of making conditioner roll lugs, as set forth in the previous object, but to additionally make lugs such that the completed radius to the exterior surfaces of the lugs is accurate and uniform whereby the rolls will be operate in a balanced fashion and, when operating in pairs, will be spaced apart by nearly the same distance, throughout their lengths.

The foregoing objects are achieved by cutting the desired lug pattern from cylindrically curved stock having a wall thickness equal to the desired thickness of the lug, and having an inside radius approximately equal to the outside radius of the conditioner roll core tube to which the lug is to be affixed. The cutting may be achieved in any manner desired including using a multi-axis laser with an indexer, high pressure water jet, or a flame cutter, or the lugs can even be made using a CNC milling machine.

These and other objects will become apparent from a reading of the ensuing description together with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a crop conditioner roll having three lobes constructed of lugs manufactured in accordance with the principles of the present invention and arranged on a cylindrical conditioner roll core in a chevron pattern.

FIG. 2 is an end view of the conditioner roll shown in FIG. 1.

FIG. 3 is a schematic view showing a piece of cylindrical tube stock supported for having lugs cut from it by a multi-axis laser cutting machine together with an indexer.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, there is shown a steel crop conditioner roll 10 including a cylindrical, tubular core 12 having a desired radius r extending to an outer cylindrical periphery to which six lugs 14 have been fixed so as to define three lobes having a chevron pattern. It is here noted that different numbers and shapes of lugs can be used and arranged to form any desired pattern.

The lugs 14 are formed as spirals and extend over one-half the length of the tubular core 12, with ends of two of the lugs abutting each other along a plane perpendicular to the longitudinal axis of the core 12. Each lug 14 has an inner radius substantially equal to the outer radius r of the core 12 and has an outer radius R which defines the working radius of the roll 10. The lugs 14 could be secured to the core 12 in any desired manner but are here shown secured to the core 12 by plug welds 16 located so as to fill a plurality of round holes 18 provided in each lug 14. It is here noted that while a complete tube is desired as the stock from which the lugs 14 are cut, a half tube or other cylindrically curved tubular portion may be used as the stock from which lugs are cut, the important criterion being that the piece of stock have a thickness equal to the desired thickness of a lug to be formed and that the inside radius of the stock be approximately equal to the outside radius r of the conditioner roll core 12.

Referring now to FIG. 3, there is shown an arrangement used in fabricating the lugs 14 which includes a laser cutting arrangement 20 for cutting lugs 14 from a piece of cylindrical tube stock 22 having an inner radius substantially equal to the radius r and having an outer radius substantially equal to the radius R. Opposite ends of the piece of cylindrical stock are held in a fixture including a first end clamp 24 which supports the tube stock 20 for rotation, and a second end clamp 26 coupled for being driven by an electric motor 28 forming part of an indexer and controlled so as to rotate the tube stock 20 about its longitudinal axis. A second electric motor 30 forms part of a laser cutter head 32 and acts for propelling the laser cutter head along a guide 34 extending parallel to the longitudinal axis of the tube stock 20. The electric motors 28 and 30 are each coupled to a control 36, which may be a programmable computer, for example.

As a beginning step in cutting lugs 14 from the tube stock 22, the control 36 causes the drive speed of the electric motors 28 and 30 to be so controlled relative to each other that the laser cutter head 32 will moved a desired distance along the length of the tube stock 22 while the tube stock 22 undergoes a desired amount of rotation, resulting in a spiral cut 38 being made, which is equal to the length of one of the lugs 14. Once an initial spiral cut 38 is made, the control 36 causes the motor 28 to index the tube stock 22 a desired amount for the placement of holes 18 in a spiral pattern spaced a desired distance from the spiral cut 38. This time, both motors 28 and 30 are caused to operated so that the laser cutter head 32 will cut the holes 18 at pre-selected locations along the length of the tube stock 22. The motor 28 then indexes the tube stock 22 so as to place it properly for the beginning of another spiral pattern of holes 18 and the motor 30 operated together with the motor 28 so as to cut the second set of holes 18. Then the motor 28 is again controlled to index the tube stock 22 to the desired location for a second spiral cut spaced from the first one by a distance for producing a lug 14 having a desired width. The motors 28 and 30 are then controlled to make the second spiral cut, which extends lengthwise of the tube stock 22 in parallel relationship to the initial spiral cut 38. The control 36 then again causes the motor 28 to be driven to rotate the tube stock to a desired location for the cutting of the next spiral set of holes 18, as described above. Operation of the motors 28 and 30 continues until all of the spiral cuts and holes are finished for the number of lugs 14 that can be made from the piece of tube stock 22. The lugs 14 are then finished and at the same time separated from the remainder of the tube stock 22 by controlling the motor 30 so that it parks the laser cutter head 32 at a first end region of the tube stock 22, with the motor 28 then being controlled to rotate the tube stock 22 while the laser cutter head is operated to make a circular cut joining first ends of all of the previously made spiral cuts. The motor 30 is then operated to move the laser cutter head to a second end region of the tube stock 22, with the motor 28 again being operated to rotate the tube stock 22 so that a second circular cut is made which joins second ends of all of the previously made spiral cuts resulting in the lugs 14 being separated from the remainder of the tube stock 22.

Thus, it can be seen that lugs 14 having the desired configuration can easily and reliably be made by first selecting stock that has parallel surfaces formed at the desired inner and outer radii. Since stock made as complete tubes or as cylindrically curved tube sections (half pipes, quarter pipes, etc) is fabricated in a manner making its dimensions very reliable, it is possible, on a repeatable basis, to make accurately dimensioned lugs resulting in accurately dimensioned conditioner rolls.

While a method of forming conditioner roll lugs is described above, it is to be understood that the same techniques can be used to form any crop processing element that is to be affixed to a cylindrical surface. For example, cutting elements for forage harvester cutter drums, lugs for crop feed rolls, and tine or brush holders for crop pick-ups could be made in accordance with the principles of the present invention

Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. 

1. A method of manufacturing a crop processing element adapted for being affixed to an exterior surface of a cylindrical core, comprising the steps of: a) selecting a length of cylindrically curved stock having a wall thickness equal to a desired crop processing element thickness, and having an inside radius substantially equal to a radius of said cylindrical core to which said crop processing element is to be affixed; and b) fabricating a crop processing element of a desired configuration from said length of cylindrically curved stock wherein a surface having a height equal to said thickness is formed for engaging crop.
 2. The method, as set forth in claim 1, wherein said cylindrically curved stock is a tube.
 3. The method, as set forth in claim 1, wherein said desired configuration is other than parallel to an axis of generation of said cylindrically curved stock.
 4. The method, as set forth in claim 1, wherein said step of fabricating includes cutting.
 5. The method, as set forth in claim 1, wherein said crop processing element is a crop conditioner roll lug.
 6. The method, as set forth in claim 5, wherein said length of cylindrically curved stock is a tube.
 7. The method, as set forth in claim 6, wherein said desired configuration is other than parallel to a longitudinal axis of said tube.
 8. The method, as set forth in claim 7, wherein said desired configuration is a spiral, with opposite sides of a given lug being fabricated by moving a cutting device along a straight path extending parallel to said longitudinal axis while rotating said tube about said axis. 